Thin Film Transistor-Liquid Crystal Display (TFT-LCD) has been widely used of various applications in flat panel display field due to characteristics of low radiation, thin thickness and low power consumption, etc. Initially, most of desktop TFT-LCD devices are based on twisted nematic (TN) mode. However, a first electrode and a second electrode of a traditional TN mode LCD device are separately formed on a first substrate and a second substrate, and liquid crystal (LC) molecules sandwiched between the first substrate and the second substrate rotate in a plane orthogonal to both the first substrate and the second substrate. Due to the optical anisotropy of the LC molecules, before entering human eyes, light beams passing through the LC molecules at different angles already have different optical path lengths, and therefore, high quality information display can only be obtained within a limited range of viewing angles.
In order to improve the viewing angle characteristics of LCDs, various methods and modes of operation have been proposed, such as in-plane switch (IPS) mode. In the conventional technology of IPS mode LCD, in order to eliminate the external static electricity, which is to prevent electrostatic moire (Mura) phenomenon, an ITO (Indium tin Oxide) layer is usually sputtered on the outer surface of the color filter substrate of the IPS mode LCD. And the ITO layer is sputtered after the color filter substrate and an array substrate respectively are being thinned and assembled to a liquid crystal panel, which virtually extends or prolongs the entire process time, making the cost greatly increased.
In order to solve the above problem, the ITO layer can be formed on the side of the color filter substrate close to the ITO layer before completing the assembly of the LCD panel. The ITO layer is electrical conducted with a common electrode of the array substrate, and then the assembly of the LCD panel is completed. In doing so, the process is simplified, thus the processing time is reduced and production costs are lower. However, in this method, since the ITO layer in the color filter substrate is electrical conducted with the common electrode of the array substrate, a relatively strong vertical electric field exists between the color filter substrate and the array substrate, which restrains the liquid crystal molecules to rotate in a plane within a certain extent. Thus, the transmittance of the LCD device is decreased, and the response time of the LCD device is slow.